sfeed

Simple RSS and Atom feed parser
git clone https://git.sinitax.com/codemadness/sfeed
Log | Files | Refs | README | LICENSE | Upstream | sfeed.txt

sfeed_web.c (3105B)

      1#include <stdio.h>
      2#include <strings.h>
      3
      4#include "util.h"
      5#include "xml.h"
      6
      7/* string and size */
      8#define STRP(s) s,sizeof(s)-1
      9
     10static XMLParser parser;
     11static int isbasetag, islinktag, ishrefattr, istypeattr;
     12static char linkhref[4096], linktype[256], basehref[4096];
     13
     14static void
     15printvalue(const char *s)
     16{
     17	for (; *s; s++)
     18		if (!ISCNTRL((unsigned char)*s))
     19			putchar(*s);
     20}
     21
     22static void
     23xmltagstart(XMLParser *p, const char *t, size_t tl)
     24{
     25	isbasetag = islinktag = 0;
     26
     27	if (!strcasecmp(t, "base")) {
     28		isbasetag = 1;
     29	} else if (!strcasecmp(t, "link")) {
     30		islinktag = 1;
     31		linkhref[0] = '\0';
     32		linktype[0] = '\0';
     33	}
     34}
     35
     36static void
     37xmltagstartparsed(XMLParser *p, const char *t, size_t tl, int isshort)
     38{
     39	struct uri baseuri, linkuri, u;
     40	char buf[4096];
     41	int r = -1;
     42
     43	if (!islinktag)
     44		return;
     45
     46	if (strncasecmp(linktype, STRP("application/atom")) &&
     47	    strncasecmp(linktype, STRP("application/xml")) &&
     48	    strncasecmp(linktype, STRP("application/rss")))
     49		return;
     50
     51	/* parse base URI each time: it can change. */
     52	if (basehref[0] &&
     53	    uri_parse(linkhref, &linkuri) != -1 && !linkuri.proto[0] &&
     54	    uri_parse(basehref, &baseuri) != -1 &&
     55	    uri_makeabs(&u, &linkuri, &baseuri) != -1 && u.proto[0])
     56		r = uri_format(buf, sizeof(buf), &u);
     57
     58	if (r >= 0 && (size_t)r < sizeof(buf))
     59		printvalue(buf);
     60	else
     61		printvalue(linkhref);
     62
     63	putchar('\t');
     64	printvalue(linktype);
     65	putchar('\n');
     66}
     67
     68static void
     69xmlattrstart(XMLParser *p, const char *t, size_t tl, const char *a, size_t al)
     70{
     71	ishrefattr = istypeattr = 0;
     72
     73	if (!isbasetag && !islinktag)
     74		return;
     75
     76	if (!strcasecmp(a, "href")) {
     77		ishrefattr = 1;
     78		if (isbasetag)
     79			basehref[0] = '\0';
     80		else if (islinktag)
     81			linkhref[0] = '\0';
     82	} else if (!strcasecmp(a, "type") && islinktag) {
     83		istypeattr = 1;
     84		linktype[0] = '\0';
     85	}
     86}
     87
     88static void
     89xmlattr(XMLParser *p, const char *t, size_t tl, const char *n, size_t nl,
     90	const char *v, size_t vl)
     91{
     92	if (isbasetag && ishrefattr) {
     93		strlcat(basehref, v, sizeof(basehref));
     94	} else if (islinktag) {
     95		if (ishrefattr)
     96			strlcat(linkhref, v, sizeof(linkhref));
     97		else if (istypeattr)
     98			strlcat(linktype, v, sizeof(linktype));
     99	}
    100}
    101
    102static void
    103xmlattrentity(XMLParser *p, const char *t, size_t tl, const char *a, size_t al,
    104              const char *v, size_t vl)
    105{
    106	char buf[8];
    107	int len;
    108
    109	if (!ishrefattr && !istypeattr)
    110		return;
    111
    112	/* try to translate entity, else just pass as data to
    113	 * xmlattr handler. */
    114	if ((len = xml_entitytostr(v, buf, sizeof(buf))) > 0)
    115		xmlattr(p, t, tl, a, al, buf, (size_t)len);
    116	else
    117		xmlattr(p, t, tl, a, al, v, vl);
    118}
    119
    120int
    121main(int argc, char *argv[])
    122{
    123	if (pledge("stdio", NULL) == -1)
    124		err(1, "pledge");
    125
    126	if (argc > 1)
    127		strlcpy(basehref, argv[1], sizeof(basehref));
    128
    129	parser.xmlattr = xmlattr;
    130	parser.xmlattrentity = xmlattrentity;
    131	parser.xmlattrstart = xmlattrstart;
    132	parser.xmltagstart = xmltagstart;
    133	parser.xmltagstartparsed = xmltagstartparsed;
    134
    135	/* NOTE: GETNEXT is defined in xml.h for inline optimization */
    136	xml_parse(&parser);
    137
    138	checkfileerror(stdin, "<stdin>", 'r');
    139	checkfileerror(stdout, "<stdout>", 'w');
    140
    141	return 0;
    142}